[Ada] Incorrect values in conversion from fixed-point subtype with 'Small

[Ada] Incorrect values in conversion from fixed-point subtype with 'Small

This patch fixes incorrect computations involving a fixed-point subtype
whose parent type has an aspect specification for 'Small.

Executing the following:

   gnatmake -q conv
   ./conv

must yield:

   9000.000000
    9.00000000000000E+03
    9000.000000
    9.00000000000000E+03
    9.00000000000000E+03
    9.00000000000000E+03
    9.00000000000000E+03
    9.00000000000000E+03

----
with Text_IO; use Text_IO;
procedure Conv is
  V_P : constant := 10.0 ** (-6);
  M_V : constant := 9000.0;
  N_V : constant := -9000.0;
  type V_T is delta V_P range N_V .. M_V  with Small => V_P;
  subtype S_T is V_T range 0.0 .. M_V;

  function Convert (Input : in S_T) return Long_Float is
  begin
    Put_Line (Input'Img);
    Put_Line (Long_Float'Image (Long_Float (Input)));
    return Long_Float (Input);
  end Convert;

begin

  declare
    Var_S : constant S_T := S_T'Last;
    Output : constant Long_Float := Convert (Var_S);
  begin
    Put_Line (Long_Float'Image (Convert (Var_S)));
    Put_Line (Long_Float'Image (Long_Float (Var_S)));
    Put_Line (Output'Img);
  end;

  Put_Line (Long_Float'Image (Long_Float (S_T'Last)));

end Conv;

2019-07-22  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* freeze.adb (Freeze_Fixed_Point_Type):  When freezing a
	fixed-point subtype, check whether the parent type declarastion
	includes an aspect specification for the 'Small type attribute,
	and inherit the specified value.

From-SVN: r273671